3.24pm GMT Christopher Pincher, a Conservative member of the committee, is asking nPower's Guy Johnson why their eco levy costs are higher than their competitors.
HSBC is leading the way, up 18.3p at 648p following Friday's news it was considering moving its headquarters out of the UK, which would save it from some of the banking levy costs it has to pay.
Carolyn Fairbairn, the CBI's director-general, said: "A spate of recent government policies, including the national living wage and the apprenticeship levy, will cost the economy around £9bn a year by 2020.
Gulliver cited the bank levy – which cost HSBC £700m last year, more than any other bank – as well as the requirement to ringfence its high street arm from the investment banking operation, as among his concerns over remaining headquartered in London.
The levy, whose cost has not been decided, has two tiers, a lower band for drinks with at least 5g of sugar per 100ml and a higher rate for those with more than 8g per 100ml.
Critics say without a binding global agreement the proposed levy will cost jobs and erode the competitiveness of Australian businesses.
Bloomberg estimates that levy will cost him about $365 million, but could be deferred indefinitely until he sells his shares.
Flint has warned that the bank levy – which costs the bank £700m a year – is a location tax.
The White House says the leaders agreed that if Russia does not take immediate steps to calm tensions in eastern Ukraine, the US and Europe will levy further costs on Moscow.
The UK bank levy, which costs HSBC £700m a year, will be part of its decision and has prompted speculation that the chancellor, George Osborne, could launch a review of the measure in his Mansion House speech on Wednesday.
